Reaction injection moldable compositions, methods for making same, and resultant golf articles

ABSTRACT

The invention relates to a method for forming golf equipment, or a portion thereof, preferably for forming one or more layers of a golf ball, including: providing a first reactable component containing an isocyanate-containing compound, and a second reactable component containing at least one polyol, polyamine, or epoxy-containing compound; mixing the reactable components together to form a reactive mixture; and injecting the reactive mixture into a cavity or mold having a desired shape within a time sufficient to avoid substantial polymerization, gelation, or solidification. Alternately, instead of providing an isocyanate-containing reactable component and at least one polyol, polyamine, or epoxy-containing compound, the method may include providing at least two sets of precursor components that can be reacted to form at least two different polymers of an interpenetrating polymer network, at least one polymer being crosslinked, wherein, if any of the at least two component sets include a mixture of precursor components, then that mixture must be sufficiently non-reactive such that the sets of precursor components, when placed in contact with each other, can still form an interpenetrating polymer network.

FIELD OF THE INVENTION

[0001] The invention relates to a reaction injection molding process andcompositions for forming golf equipment or components thereof,particularly for forming layers of golf balls in one embodiment. Thereaction injection molding process of the invention involves providingat least two reactable components that have a fast reaction time andinjecting them with sufficient speed after they are mixed so that theyare polymerized, solidified, or gelled in a mold cavity.

BACKGROUND OF THE INVENTION

[0002] It is well known to even the average golfer that the equipmentused in playing the game is subject to a great deal of friction, impact,and other stresses during a typical round of golf. Both the performanceand the useful life of such equipment would benefit from the use ofmaterials having increased durability. For instance, many types of golfclubs, such as putters, drivers, and wedges, contain polymer inserts inthe face of the club. Since the club face directly strikes a golf ballthousands of times over the life of the club, improved durability is ofgreat importance. Additionally, club components, such as shafts, grips,and hosels, undergo significant stress during a golf swing and contactwith a golf ball and, therefore, could stand to benefit from moredurable materials.

[0003] Of course, golf balls are repeatedly struck against very hardobjects as well, including golf clubs, and it is very desirable tomaintain their performance properties over as long a period of time aspossible. Golfers of all skill levels seek out a variety of propertiesin their golf balls for a variety of golfing situations, althoughresilience, durability, and longevity are always important. The type ofmaterials used in forming the different golf ball layers can greatlyaffect these properties, as well as the “click,” “feel,” spin, initialvelocity, “playability,” and other properties.

[0004] Golf equipment is typically formulated from a variety ofdifferent materials. Most conventional materials, however, do notentirely address the problems associated with stress, durability, andrepeated impact. Therefore, it is clear that improved materials, havingmaterial properties that address these preferred physical requirements,are necessary.

[0005] In addition, the manner in which golf equipment, or componentsthereof, is fabricated can affect certain properties of the materials,for example, such as durability. The types of chemistries present in thegolf equipment materials can also sometimes indicate or dictate thepreferred method of fabrication used to form them.

[0006] Particularly with respect to polyurethane-containing materials,commercially available golf equipment or components, especially for golfballs, can be currently made by casting or injection molding processes.The nature of current casting processes is such that materials thatrequire a relatively long time (in comparison to other fabricationmethods) to sufficiently solidify, i.e., react thoroughly. As a result,materials or compounds with particular chemistries that react orsolidify relatively quickly are generally restricted from use incommercial casting processes, particularly in the golf art.

[0007] By using an alternative fabrication technique, reaction injectionmolding, as opposed to traditional injection molding, thermosettingmaterials and/or materials with relatively quick reaction orsolidification times can be processed into certain articles. Reactioninjection molding processes, due to the nature of the chemistries of thematerials used, tend to result in decreased fabrication times, and canfacilitate a decrease in the cost of fabricating such articles. Thetechnique of reaction injection molding (RIM) using a variety ofmaterials has been demonstrated in various publications.

[0008] For example, U.S. Pat. No. 4,762,322 discloses golf clubs withheads that can be made from a hollow metal shell or a low density, highstrength material, such as a reaction injection molded polyurethane,formed around weighted inserts.

[0009] With respect to manufacture of golf balls, RIM has beendisclosed, for example, in International Publication No. WO 00/57962,which claims golf balls, and processes for making such balls, comprisinga reaction injection molded material, such as polyurethanes/polyureas.

[0010] In addition, U.S. Pat. No. 6,083,119 discloses a multi-layer golfball with an inner and outer cover layer, at least one of which cancontain a reaction injection molded polyurethane material.

[0011] U.S. Pat. Nos. 4,695,055 and 4,878,674 also disclose illuminated,translucent golf balls having a permanent diametric hole into which achemiluminescent light stick is added, so that the golf balls may bevisible in the dark. These golf balls can be fabricated by a method suchas reaction injection molding.

[0012] Additionally, conventional non-reactive injection molding can beused to form relatively thin layers of material in golf equipment, orcomponents thereof, generally in golf balls. Examples of thin componentsor layers made by conventional non-reactive injection molding have alsobeen demonstrated in various publications.

SUMMARY OF THE INVENTION

[0013] One aspect of the invention relates to a method for forming golfequipment, or a portion thereof, preferably for forming one or morelayers of a golf ball, including: providing a first reactable componentincluding an isocyanate-reactive component, preferably including apolyisocyanate or including a prepolymer or quasi-prepolymer containingthe reaction product of a polyol, polyamine, or epoxy-containingcompound with at least one polyisocyanate, and a second reactablecomponent including at least one of a polyol, polyamine, orepoxy-containing compound; combining the reactable components togetherto form a reactive mixture; and injecting the reactive mixture into acavity or mold having a desired shape within a time sufficient to avoidsubstantial gelation or solidification. Advantageously, thepolymerization, solidification, or gelation times of the reactivemixture of the present invention should typically be within about 60seconds, preferably within about 45 seconds, more preferably from about0.25 seconds to 30 seconds, most preferably from about 0.5 seconds to 15seconds, after combining, either at ambient or elevated temperatures. Invarious other embodiments, the polymerization, solidification, orgelation times of the reactive mixture of the present invention are fromabout 1 second to 10 seconds or from about 1 second to 5 seconds aftercombining.

[0014] In a preferred embodiment, each of the at least two reactablecomponents have a viscosity not more than about 20,000 cPs, preferablynot more than about 15,000 cPs, more preferably from about 25 cPs to10,000 cPs, most preferably from about 25 cPs to 5,000 cPs, all atambient or elevated temperatures. In another preferred embodiment, allthe reactable components, or mixtures thereof each contained separately,that form the reactive mixture have viscosities similar to those of thefirst and second reactable components at ambient or elevatedtemperatures. In yet another preferred embodiment, each reactablecomponent has a viscosity not more than about 5,000 cPs, preferably notmore than about 1,000 cPs, at a temperature of about 150° F. In oneembodiment, the mixture is injected into the mold or cavity at aninjection pressure of not more than about 2,500 psi. In anotherembodiment, the viscosity index of any two of the reactable componentsis from about 1000 to 1, preferably from about 800 to 20, at ambienttemperature or at a temperature at which the reactable components arecombined.

[0015] In one preferred embodiment, the isocyanate-containing compoundor the polyisocyanate includes a diisocyanate having the genericstructure:

O═C═N—R—N═C═O

[0016] where R is a cyclic, aromatic, or linear branched or unbranchedhydrocarbon chain each having a moiety containing from about 1 to 20carbon atoms. When multiple aromatic or cyclic groups are present,linear and/or branched hydrocarbons containing from about 1 to 10 carbonatoms can be present as spacers between the aromatic or cyclic groups.In some cases, the cyclic or aromatic group(s) may be substituted at the2-, 3-, and/or 4-positions, or at the ortho-, meta-, and/or para-positions, respectively, with: halogens; primary, secondary, or tertiaryhydrocarbon groups; or a mixture thereof. In another preferredembodiment, the isocyanate-containing compound or the polyisocyanateincludes higher functional adducts of diisocyanates, e.g., such as theisocyanurate of TDI, the isocyanurate of a hexamethylene diisocyanate,the uretdione of TDI, the uretdione of HDI, or a mixture thereof. In yetanother preferred embodiment, the isocyanate-containing compound or thepolyisocyanate includes a triisocyanate or higher functionalpolyisocyanate that is not an adduct of a diisocyanate, or a mixturethereof. In a more preferred embodiment, the polyisocyanate containsPPDI, MPDI, MDI, or TDI, more preferably MDI. In one preferredembodiment, the second reactable component can include more than onepolyol, polyamine, or epoxy-containing compound, at least one compoundwhich preferably has a molecular weight less than about 400 g/mol, andat least a second compound of which is preferably a polyether polyol, ahydroxy-terminated polybutadiene, a polyester polyol, a polycarbonatepolyol, or a mixture thereof, more preferably a partially or fullyhydrogenated hydroxy-terminated polybutadiene. In this preferredembodiment, the second reactable component preferably has a numberaverage molecular weight of not less than about 200 g/mol, morepreferably from about 200 g/mol to 4,000 g/mol. In one embodiment, thesecond polyol, polyamine, or epoxy-containing compound mayadvantageously be present in an amount from about 40% to 95% based onthe total weight of the first and second reactable components. Inanother embodiment, the total amount of the first reactable componentplus the first polyol, polyamine, or epoxy-containing compound mayadvantageously be from about 5% to 60% based on the total weight of thefirst and second reactable components. In one preferred embodiment, thefirst reactable component includes greater than about 14% by weight ofunreacted isocyanate groups. In another preferred embodiment, the firstreactable component includes less than about 14% by weight of unreactedisocyanate groups. In yet another preferred embodiment, the firstreactable component includes a low free isocyanate monomer composition.

[0017] Another aspect of the invention relates to a method for forminggolf equipment, or a portion thereof, including: providing at least twosets of precursor components that can be reacted to form at least twodifferent polymers of an interpenetrating polymer network, at least onepolymer being crosslinked; combining the sets of precursor componentstogether to form a reactive mixture; and injecting the reactive mixtureinto a cavity or mold having a desired shape within a time sufficient toavoid substantial polymerization, gelation, or solidification. In onepreferred embodiment, the at least two sets of precursor componentsinclude a first reactable component, which contains anisocyanate-containing compound, and a second reactable component, whichcontains an isocyanate-reactive compound.

[0018] Another aspect of the invention relates to a method for forminggolf equipment, or a portion thereof, including: providing at least tworeactable components that, when combined, can form a foamed polymericmaterial; combining the reactable components together to form a reactivemixture; and injecting the reactive mixture into a cavity or mold havinga desired shape within a time sufficient to avoid substantialpolymerization, gelation, or solidification, and such that the reactivemixture forms a foamed material, preferably an open-cell, a closed-cell,or a microcellular foam, also preferably with a specific gravity of notmore than about 1, more preferably not more than about 0.8, mostpreferably not more than 0.5.

[0019] In one embodiment where the golf equipment that is formedincludes one or more layers of a golf ball, the golf ball can have asolid or fluid-filled center, optionally at least one intermediate layerdisposed about the center, and at least one cover layer disposed aboutthe center and the optional intermediate layer, if present. In oneembodiment, the cover layer of the golf ball has a first materialhardness and the layer disposed immediately inside the cover layer has asecond material hardness, and the first material hardness is greaterthan the second material hardness. In that embodiment, the firstmaterial hardness can be at least about 55 Shore D, or the secondmaterial hardness can be up to about 55 Shore D. In another embodiment,the second material hardness is greater than the first materialhardness. In that embodiment, the first material hardness can be up toabout 55 Shore D, or the second material hardness can be at least about55 Shore D. In yet another embodiment, the cover material hardness isgreater than about 15 Shore A. In a preferred embodiment, the core ofthe golf ball has an outer diameter from about 1.55 inches to 1.67inches. In another embodiment, the injecting results in the formation ofgolf equipment, or a portion thereof, which has a thickness less thanabout 0.065 inches, alternately less than 0.01 inches. In anotherpreferred embodiment, the equipment has a coefficient of restitution ofgreater than about 0.7, preferably greater than about 0.75, and morepreferably greater than about 0.78, at an initial velocity of 125 ft/s.In another preferred embodiment, the golf ball, or a portion thereof,has an Atti compression of at least about 40, preferably from about 50to 120, more preferably from about 60 to 100.

[0020] In one embodiment, the injecting or the method results in theformation of golf equipment, or a layer or portion thereof, which layeror portion has a moisture vapor transmission rate (“MVTR”) of less thanabout 1000 (g.mil)/(100 in².day), preferably less than about 750(g.mil)/(100in².day), more preferably less than about 500 (g.mil)/(100in².day).

[0021] In an embodiment where the golf equipment includes a golf ball ora portion thereof, the method according to the invention furtherincludes optionally adding from about 0.1% to 50% by weight of a fillermaterial. Adding this filler material may alter the specific gravity orother mechanical, physical, optical, or processing properties of thegolf ball or the portion thereof.

[0022] In another embodiment, the method further includes adding to oneor more of the reactable components a catalyst to facilitate or speed upthe reaction between the at least two reactable components when they arecombined. Preferably, the catalyst is present in an amount from about0.001% to 3% by weight and includes a metal catalyst, preferably a tincatalyst, an amine catalyst, an organic acid, a delayed catalyst, or acombination thereof.

[0023] Another aspect of the invention relates to golf equipment,preferably golf balls, or a portion thereof, prepared by any of theprocesses detailed herein. For example, the invention includes golfequipment, or a portion thereof, including: a first reactable componentcomprising an isocyanate-containing compound; and a second reactablecomponent comprising at least one of a polyol, polyamine, orepoxy-containing compound, wherein the golf equipment, or portionthereof, is formed by reaction injection molding of the first and secondreactable components, which react with each other after contactsufficiently to be substantially gelled or solidified within about 60seconds, and wherein the isocyanate-containing compound contains: adiisocyanate having the generic structure, O═C═N—R—N═C═O, where R is amoiety containing from about 1 to 20 carbon atoms, optionally includingone or more substituted or unsubstituted phenyl or cyclic groups; adimeric or multimeric adduct of a diisocyanate; a triisocyanate orhigher functional polyisocyanate that is not an adduct of adiisocyanate; or a mixture thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Further features and advantages of the invention can beascertained from the following detailed description that is provided inconnection with the drawings described below:

[0025]FIG. 1 illustrates a golf ball including a center and a coverlayer disposed over the center, in which at least one of the center orthe cover layer includes a reaction injection molded material accordingto the invention;

[0026]FIG. 2 illustrates a three-layer golf ball, in which at least onelayer of the golf ball includes a reaction injection molded materialaccording to the invention;

[0027]FIG. 3 illustrates a multi-layer golf ball, in which at least onelayer of the golf ball includes a reaction injection molded materialaccording to the invention; and

[0028]FIG. 4 illustrates a hemispherical grid scaffolding useful informing a portion of an intermediate layer of a golf ball according tothe invention.

[0029] These FIGS. are not necessarily drawn to scale.

DEFINITIONS

[0030] As used herein, the term “golf equipment” includes any type ofequipment used in connection with golf, including, but not limited to,golf balls; golf clubs (e.g., putters, drivers, and wedges) and clubattachments, additions, or modifications, such as striking face inserts;golf club components (e.g., shafts, hosels, and grips); golf clubvibration damping devices; golf gloves; golf shoes; and any portion ofthe above items.

[0031] As used herein, the phrase “substantial gelation orsolidification” refers generally to viscosity increases sufficient toprevent or substantially retard flow of a material into a mold or cavityor through an orifice.

[0032] The term “catalyst,” as used herein, should be understood by oneof ordinary skill in the art to include only those compounds whichfacilitate, or increase the rate of, a particular reaction and which arenot substantially consumed by themselves reacting with one or more ofthe necessary components of the particular reaction. For example, anycompound containing an accessible and reactive amine, epoxy, or hydroxylgroup that should readily react with an isocyanate group should beconsidered a reactable component (e.g., a curing agent) and not acatalyst.

[0033] As used herein, the term “fluid” includes a liquid, a paste, agel, a gas, or any combination thereof. It should be understood that theterm “fluid-filled,” as used herein in reference to golf equipment or toa portion thereof, also includes the situation where the golf equipment,or the portion thereof, is hollow.

[0034] As used herein in reference to a golf ball, the term “core”represents the center and optional additional layer(s), such as anintermediate layer, which layer(s) is(are) disposed between the centerand the cover of the golf ball.

[0035] The term “prepolymer,” as used herein, refers to a materialcontaining at least one isocyanate-containing component, and at leastone isocyanate-reactive component, for example, such as a polyol, apolyamine, an epoxy-containing compound, and mixtures thereof.

[0036] The term “quasi-prepolymer,” as used herein, refers to a subsetof prepolymers in which the isocyanate content is at least about 13% ofthe weight of the prepolymer. Where prepolymers are mentioned herein, itshould be understood that this includes prepolymers having an isocyanatecontent less than about 13% by weight and also includesquasi-prepolymers.

[0037] The term “polyol,” as used herein, refers to a compoundcontaining at least 2 hydroxyl groups, regardless of its molecularweight. The term “polyamine,” as used herein, refers to a compoundcontaining at least 2 primary or secondary amine groups, regardless ofmolecular weight.

[0038] The term “viscosity index,” as used herein, refers to the ratioof viscosities between two components. As should be understood by one ofordinary skill in the art, solid components generally do not have ameasurable viscosity.

[0039] The term “substantially,” as used herein referring to an amountor condition, means at least about 80%, preferably at least about 90%,more preferably at least about 95%, most preferably at least about 99%of the amount or condition.

[0040] The term “about,” as used herein before a range of values, shouldbe understood to modify either or both of the values in the range.

[0041] As used herein with regard to golf ball properties, the term“compression” refers to Atti compression, which is defined as thedeflection of an object or material relative to the deflection of acalibrated spring, as measured with an Atti Compression Gauge, that iscommercially available from Atti Engineering Corp. of Union City, N.J.Atti compression is typically used to measure the compression of a golfball. When the Atti Gauge is used to measure cores having a diameter ofless than 1.680 inches, it should be understood that a metallic or othersuitable shim is used to make the measured object 1.680 inches indiameter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The invention relates to a method for forming golf equipment, ora portion thereof, in particular for forming one or more layers of agolf ball, including: providing a first reactable component including apolyisocyanate or including a prepolymer or quasi-prepolymer containingthe reaction product of a polyol, polyamine, or epoxy-containingcompound with at least one polyisocyanate, and a second reactablecomponent including at least one of a polyol, polyamine, orepoxy-containing compound; mixing the reactable components together toform a reactive mixture; and injecting the reactive mixture into acavity or mold having a desired shape within a time sufficient to avoidsubstantial gelation or solidification. Advantageously, thepolymerization, solidification, or gelation times of the reactivemixture of the present invention should typically not be more than about60 seconds, preferably not more than about 45 seconds, more preferablyfrom about 0.25 seconds to 30 seconds, most preferably from about 0.5seconds to 15 seconds, all at ambient or elevated temperatures. Invarious other embodiments, the polymerization, solidification, orgelation times of the reactive mixture of the present invention are fromabout 1 second to 10 seconds or from about 1 second to 5 seconds. Inparticular, reaction injection molding can be used to form a core layer,intermediate layer, cover layer, or any portion or combination of layersthereof.

[0043] Reaction injection molding (“RIM”) according to the inventionincludes any injection molding process in which two or more componentsare reactive upon contact and/or addition into a mold cavity. Theinvention further includes several different subtypes of reactioninjection molding, e.g., such as liquid injection molding (“LIM”),reinforced reaction injection molding (“RRIM”), and structural reactioninjection molding (“SRIM”). Liquid injection molding occurs when the twoor more components are in liquid form and includes subclasses micro-LIMand nano-LIM, which refer to smaller and much smaller injection volumes,respectively, as compared to most commercial processes. Reinforced RIMoccurs with one or more filler materials being added to the two or morecomponents prior to injection into the mold cavity. Structural RIMoccurs where there is a preform around which the two or more componentsare injected within the mold cavity. The preform is generally in fiberor mesh form but may be made from any material sufficient tosubstantially withstand the injection pressures typically associatedwith the RIM process. In SRIM, a composite material is typically formed.

[0044] In a preferred embodiment, each of the first and second reactablecomponents have a viscosity not more than about 20,000 cPs, preferablynot more than about 15,000 cPs, more preferably from about 25 cPs to10,000 cPs, most preferably from about 25 cPs to 5,000 cPs, until thereactable components are mixed together or the reactive mixture isinjected into the cavity or mold. In another preferred embodiment, allthe reactable components, or mixtures thereof, that can be contacted toform the reactive mixture have viscosities similar to those of the firstand second reactable components. In yet another preferred embodiment,each reactable component has a viscosity not more than about 5,000 cPsat a temperature of about 150° F. In one embodiment, the mixture isinjected into the mold or cavity at an injection pressure of not morethan about 2,500 psi.

[0045] These polymerization, solidification, or gelation times, as wellas the viscosities of the reactable components, are applicable atambient temperature (i.e., about 20° C. to 30° C.) or at elevatedtemperatures, for example, such as those at which the reactablecomponents are separately contained or those at which the reactivemixture is injected. Preferably, when the polymerization,solidification, or gelation times, or the viscosities of the reactablecomponents, are applied at elevated temperatures, the elevatedtemperature is typically the temperature at which the reactive mixtureis injected.

[0046] The first, or isocyanate-containing, reactable component caninclude any isocyanate-functional monomer, or a dimeric or multimericadduct thereof, prepolymer, quasi-prepolymer, or mixture thereof. Theisocyanate-functional compounds may include monoisocyanates orpolyisocyanates, which include any isocyanate functionality of 2 ormore. Any polyisocyanate available to one of ordinary skill in the artis suitable for use according to the invention. Suitableisocyanate-containing components include diisocyanates having thegeneric structure:

O═C═N—R—N═C═O

[0047] where R is preferably a cyclic, aromatic, or linear or branchedhydrocarbon moiety containing from about 1 to 20 carbon atoms. Thediisocyanate may also contain one or more phenyl groups or one or morecyclic groups. When multiple aromatic or cyclic groups are present,linear and/or branched hydrocarbons containing from about 1 to 10 carbonatoms can be present as spacers between the aromatic or cyclic groups.In some cases, the cyclic or aromatic group(s) may be substituted at the2-, 3-, and/or 4-positions, or at the ortho-, meta-, and/or para-positions, respectively. Substituted groups may include, but are notlimited to, halogens; primary, secondary, or tertiary hydrocarbongroups; or a mixture thereof. Other suitable isocyanate-containingcompounds or the polyisocyanates include higher functional adducts ofthe above diisocyanates, as well as triisocyanates and higher functionalisocyanates that are not adducts of diisocyanates, and mixtures thereof.Exemplary polyisocyanates include, but are not limited to, straight orbranched aliphatic diisocyanates containing from about 2 to 40 carbons,for example, such as ethylene diisocyanate, propylene isocyanates (e.g.,such as propylene-1,2-diisocyanate), tetramethylene isocyanates (e.g.,such as tetramethylene-1,4-diisocyanate), hexamethylene diisocyanates(e.g., such as 1,6-hexamethylene diisocyanate (“HDI”),2,2,4-trimethylhexamethylene diisocyanate (“TMDI”), and the like),dodecane-1,12-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate,4,4′-dicyclohexylmethane diisocyanate (“H₁₂MDI”), 2,4,4-trimethylenediisocyanate, and the like; diisocyanates containing cyclic groups, forexample, such as cyclobutane-1,3-diisocyanate, cyclohexyl diisocyanates(e.g., such as cyclohexane-1,3-diisocyanate,cyclohexane-1,4-diisocyanate, methyl cyclohexylene diisocyanate(“H₆XDI”), 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane,isophorone diisocyanate (“IPDI”), and the like); diisocyanatescontaining aromatic groups, for example, such as 4,4′-diphenylmethanediisocyanate (“MDI”), polymeric MDI, carbodiimide-modified liquid MDI,p-phenylene diisocyanate (“PPDI”), m-phenylene diisocyanate (“MPDI”),toluene diisocyanate (“TDI”), 3,3′-dimethyl-4,4′-biphenylenediisocyanate (“TODI”), naphthalene diisocyanate (“NDI”), xylylenediisocyanate (“XDI”), para-tetramethylxylylene diisocyanate (“p-TMXDI”),meta-tetramethylxylylene diisocyanate (“m-TMXDI”), tetracenediisocyanate, napthalene diisocyanate, anthracene diisocyanate, and thelike; trimerized isocyanurates of any polyisocyanate or mixturesthereof, for example, such as the isocyanurate of TDI, the isocyanurateof a hexamethylene diisocyanate, and the like; dimerized uretdiones ofany polyisocyanate or mixtures thereof, for example, such as theuretdione of TDI, the uretdione of a hexamethylene diisocyanate (e.g.,such as HDI and the like), and the like; and mixtures thereof.Polyisocyanates are known to those of ordinary skill in the art ashaving more than one isocyanate group, e.g., di-, tri-, andtetra-isocyanate. Preferably, the polyisocyanate includes MDI, PPDI,MPDI, TDI, or a mixture thereof. In one preferred embodiment, thepolyisocyanate includes MDI. In one embodiment, the polyisocyanate iscompletely free of m-TMXDI. It should be understood that, as usedherein, the term “MDI” includes 4,4′-diphenylmethane diisocyanate,polymeric MDI, carbodiimide-modified liquid MDI, and mixtures thereof.

[0048] Typically, the amount of the isocyanate-containing reactablecomponent is determined in relation to the amount of the secondreactable component present in the reactive mixture. In one preferredembodiment, the ratio of the first isocyanate-containing reactablecomponent to the second, or isocyanate-reactive, reactable component istypically from about 0.02:1 to 10:1, preferably from about 2:1 to 1:2,more preferably from about 1.5:1 to 1:1.5, most preferably from about1.1:1 to 1:1.1.

[0049] In one embodiment, the first isocyanate-containing reactablecomponent should have less than about 14% by weight unreacted NCOgroups, based on the weight of the isocyanate-containing reactablecomponent. In another embodiment, the first isocyanate-containingreactable component has no greater than about 7.5%, more preferably fromabout 2.5% to 7.5%, and most preferably from about 4% to 6.5% by weightunreacted NCO groups, based on the weight of the firstisocyanate-containing reactable component. In yet another embodiment,the first isocyanate-containing reactable component should have greaterthan about 14% by weight unreacted NCO groups, based on the weight ofthe isocyanate-containing reactable component.

[0050] The first isocyanate-containing reactable component employed maybe “low free monomer,” understood by one of ordinary skill in the art tohave lower levels of “free” monomer isocyanate groups, typically lessthan about 0.1% free isocyanate-containing monomer groups. Typically,polymer products containing low free monomer isocyanates are less toxic,exhibit improved elastomeric properties, and/or result in a more uniformpolymer. Examples of “low free monomer” isocyanates include, but are notlimited to, Low Free Monomer MDI, Low Free Monomer TDI, and Low FreeMonomer PPDI, as well as mixtures thereof.

[0051] Preferably, the second reactable component includes at least onepolyamine, polyol, epoxy-containing compound, or a mixture thereof Inone preferred embodiment, the second reactable component includes atleast one polyamine. Suitable polyamines include, but are not limitedto, tetrahydroxypropylene ethylenediamine;3,5-dimethylthio-2,4-toluenediamine and isomers thereof, for example,such as 3,5-dimethylthio-2,6-toluenediamine or ETHACURE™ 300,commercially available from Albermarle Corporation of Baton Rouge, La.;3,5-diethyltoluene-2,4-diamine and isomers thereof, such as3,5-diethyltoluene-2,6-diamine; 1,4-bis-(sec-butylamino)-benzene andisomers thereof, for example, such as 1,2-bis-(sec-butylamino)-benzene;1,2-bis-(sec-butylamino)cyclohexane and isomers thereof, for example,such as 1,4-bis-(sec-butylamino)cyclohexane;4,4′-bis-(sec-butylamino)-diphenylmethane and derivatives thereof;4,4′-bis(sec-butylamino)-dicyclohexylmethane and derivatives thereof;trimethylene glycol di-paminobenzoate;polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenylmethane; p,p′-methylene dianiline (“MDA”); m-phenylenediamine (“MPDA”);4,4′-methylene-bis-(2-chloroaniline) (“MOCA”);4,4′-methylene-bis-(2,6-diethylaniline);4,4′-methylene-bis-(3-chloro-2,6-diethylaniline);4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane;2,2′,3,3′-tetrachloro-diamino diphenylmethane; 4,4′-dicyclohexylmethanediamine; m- or p- phenylenediamine; 1,4-cyclohexyl-bis-(methylamine) andisomers thereof, for example, such as 1,4-cyclohexyl-bis-(methylamine);2-methylpenatmethylene diamine; diaminocyclohexane; triisopropanolamine;diethylene triamine; triethylamine tetramine; tetraethylene pentamine;isomers of propylenediamine, for example, such as 1,3-propylenediamine;dialkylaminopropylamines, for example, such as dimethylaminopropylamine,diethylaminopropylamine, and the like, and mixtures thereof,imido-bis-propylamine; diethanolamine; triethanolamine;diisopropanolamine; isophoronediamine; and mixtures thereof. Suitablepolyamines, which can include both primary and secondary amines,preferably have molecular weights ranging from about 64 to 4,000 g/mol.

[0052] Other suitable polyamines include those having the generalformula:

[0053] where n and m each separately have values of 0, 1, 2, or 3, andwhere Y is preferably 1,2-cyclohexyl, 1,3-cyclohexyl, 1,4-cyclohexyl,o-, m-, orp- phenylene, or the like, or a combination thereof.Preferably, n and m each separately have values of 0, 1, or 2, morepreferably 1 or 2.

[0054] In an alternate preferred embodiment, the second reactablecomponent includes a polyol. Any polyol, or mixture thereof, availableto one of ordinary skill in the art is suitable for use according to theinvention. In a more preferred embodiment, the polyol includes ethyleneglycol; diethylene glycol; propylene glycol; dipropylene glycol; apolyether polyol, for example, such as polyethylene glycol,polypropylene glycol, polytetramethylene ether glycol (M_(n)≦about 4,000g/mol), and the like, and mixtures thereof; 1,3-bis(2-hydroxyethoxy)benzene; 1,3-bis-[2-(2-hydroxyethoxy) ethoxy]benzene;1,3-bis-{2-[2-(2-hydroxyethoxy) ethoxy]ethoxy}benzene; 1,3-butanedioland isomers thereof, for example, such as 1,4-butanediol,2,3-butanediol, and the like, and mixtures thereof; 1,5-pentanediol;1,6-hexanediol; ortho-phthalate-1,6-hexanediol;resorcinol-di(β-hydroxyethyl) ether and its derivatives;hydroquinone-di-(β-hydroxyethyl) ether and its derivatives; trimethylolpropane; hydroxy-terminated polybutadiene (including partially/fullyhydrogenated derivatives); a polyester polyol, for example, such as apolycaprolactone polyol; polycarbonate polyol; or a mixture thereof.

[0055] When the polyol includes a polyether polyol, preferably thosepolyols that have the generic structure:

[0056] where R₁ and R₂ are straight or branched hydrocarbon chains, eachcontaining from 1 to about 20 carbon atoms, and n ranges from 1 to about45. Examples include, but are not limited to, polytetramethylene etherglycol (“PTMEG”), polyoxyethylene glycol (“PEG”), polyoxypropyleneglycol (“PPG”), poly(oxyethylene-oxypropylene) glycol copolymers, andmixtures and copolymers thereof. The hydrocarbon chain can havesaturated or unsaturated bonds and substituted or unsubstituted aromaticand cyclic groups. In a preferred embodiment, the polyol of the presentinvention includes PTMEG.

[0057] When polyester polyols are included in the polyurethane materialof the invention, preferably those polyols that have the genericstructure:

[0058] where R₁ and R₂ are straight or branched hydrocarbon chains, eachcontaining from 1 to about 20 carbon atoms, and n ranges from 1 to about25. Suitable polyester polyols include, but are not limited to,polyethylene adipate glycol, polypropylene adipate glycol, polybutyleneadipate glycol, poly(ethylene adipate-propylene adipate) glycol,poly(hexamethylene adipate) glycol, and mixtures and copolymers thereof.The hydrocarbon chain can have saturated or unsaturated bonds, orsubstituted or unsubstituted aromatic and cyclic groups.

[0059] In an alternate preferred embodiment, the polyester polyol caninclude a polycyclic ester polyol, for example, such as apolycaprolactone polyol. When polycaprolactone polyols are included inthe materials of the invention, preferably those polyols that have thegeneric structure:

[0060] where R₁ is preferably a straight chain or branched hydrocarbonchain containing from 1 to about 20 carbon atoms, and where n is thechain length and ranges from 1 to about 20. Suitable polycaprolactonepolyols include, but are not limited to, 1,6-hexanediol-initiatedpolycaprolactone, diethylene glycol-initiated polycaprolactone,trimethylol propane-initiated polycaprolactone, neopentylglycol-initiated polycaprolactone, 1,4-butanediol-initiatedpolycaprolactone, PTMEG-initiated polycaprolactone, and mixturesthereof. The hydrocarbon chain can have saturated or unsaturated bonds,or substituted or unsubstituted aromatic and cyclic groups.

[0061] When polycarbonate polyols are included in the polyurethanematerial of the invention, preferably those polyols that have thegeneric structure:

[0062] where R₁ can include a hydrocarbon chain, which may havesaturated or unsaturated bonds or substituted or unsubstituted aromaticor cyclic groups (e.g., in one preferred embodiment, R₁ includespredominantly bisphenol A units -(p-C₆H₄)—C(CH₃)₂-(p-C₆H₄)— orderivatives thereof), and where the chain length, n, ranges from 1 toabout 20. Suitable polycarbonates include, but are not limited to,poly(phthalate carbonate) glycol, poly(hexamethylene carbonate) glycol,polycarbonate glycols containing bisphenol A, or mixtures or copolymersthereof.

[0063] Other suitable polyols have the following general chemicalstructure:

[0064] where n and m each separately have values of 0, 1, 2, or 3, andwhere X is o-phenylene, m-phenylene, p-phenylene, 1,2-cyclohexyl,1,3-cyclohexyl, or 1,4-cyclohexyl, or mixtures thereof. Preferably, nand m each separately have values of 0, 1, or 2, and more preferably, 1or2.

[0065] In one embodiment, the second reactable component contains acompound having a molecular weight of at least about 400 g/mol,alternately from about 200 g/mol to about 4000 g/mol. In anotherembodiment, the second reactable component contains a compound having amolecular weight of not more than about 400 g/mol, alternately fromabout 18 g/mol to 600 g/mol. In a preferred embodiment, the secondreactable component contains at least two compounds, a first compoundhaving a molecular weight of not less than about 400 g/mol, alternatelyfrom about 200 g/mol to about 4000 g/mol, and a second compound having amolecular weight of not more than about 400 g/mol, alternately fromabout 18 g/mol to 600 g/mol. It should be understood that molecularweight, as used herein, is the absolute number average molecular weightand would be understood as such by one of ordinary skill in the art.

[0066] Generally, when the second reactable component contains acompound whose molecular weight is not less than about 400 g/mol, thisreactable component is considered the “soft segment” of the resultingpolymer material. Preferably, the soft segment is present in an amountfrom about 40% to 95%, preferably from about 50% to 90%, more preferablyfrom about 60% to 85%, based on the total weight of the polymer.

[0067] Epoxy-containing compounds according to the present inventionhave the general formula:

[0068] wherein R₁ and R₂ can be the same or different and each representa hydrogen atom or an organic group including linear and branched chainalkyl, aryl, hydrocarbyloxy, and carbocyclic groups, and mixturesthereof. In a preferred embodiment, both R₁ and R₂ are generally nothydrogen atoms.

[0069] As used herein, the phrase linear chain or branched chained alkylgroups of up to about 30 carbon atoms means any substituted orunsubstituted acyclic carbon-containing compounds. Examples of alkylgroups include lower alkyl, for example, methyl, ethyl, n-propyl,iso-propyl, n-butyl, iso-butyl or tert-butyl; and upper alkyl, forexample, octyl, nonyl, decyl, etc.

[0070] In addition, such alkyl group may also contain varioussubstituents in which one or more hydrogen atoms has been replaced by afunctional group. Functional groups include but are not limited tohydroxyl, amino, carboxyl, amide, ester, ether, halogen (fluorine,chlorine, bromine and iodine), siloxanes, and sulfonic amides to mentionbut a few.

[0071] As used herein, substituted and unsubstituted carbocyclic groupsof up to about 20 carbon atoms means cyclic carbon-containing compounds,including but not limited to cyclopentyl, cyclohexyl, and a combinationthereof.

[0072] A preferred class of epoxy-containing compounds for the presentinvention includes organic compounds having two epoxy groups as shown inthe formula below:

[0073] wherein R is defined as for R₁ and R₂ above.

[0074] The most preferred diepoxy compound for use in the secondreactive component of the present invention is (2,2-bis[4-(2′3′ epoxypropoxy)phenyl]propane), commonly called the diglycidyl ether ofbisphenol A (DGEBA) and having the following formula:

[0075] The other curing agents, related to DGEBA may also be used in thepresent invention. The higher molecular weight homologs are representedby the following theoretical structure having the following formula:

[0076] Typical values of n can be from 0.5 to about 2.5 and is about 0.15 for D.E.R. 331 epoxy resin (epoxy equivalent weight range of about182 to 192 and viscosity of 11,000-14,000 cps). The low melting pointsolid resins begin at an “n” of about 2.5. In high melting point solidresins, n may be as high as 18.

[0077] Other organic compounds having at least one epoxy group which,according to the claimed invention, can be used in one of the reactablecomponents include the epoxy-novolac resins under the trade name D.E.N.(400 series), such as D.E.N. 431, D.E.N. 438 and D.E.N. 439, availablefrom Dow Chemical Co. Further, low viscosity polyglycol epoxy resinsunder the trade name D.E.R. (700 series), including D.E.R. 732 andD.E.R. 736 may also be used. Also, the EPON™ class of epoxy resinavailable from SHELL can also be used in the golf equipment or methodsaccording to the present invention.

[0078] The polyols, polyamines, and epoxy-containing compounds caninclude one or more saturated, unsaturated, aromatic, and cyclic groups.Additionally, the polyols, polyamines, and epoxy-containing compoundscan include one or more halogen groups. Also, a single polyol,polyamine, or epoxy-containing compound may be used, as well as a blendor mixture thereof.

[0079] In some embodiments, catalysts may optionally be used toaccelerate or facilitate the reaction between the isocyanate-containingcomponent and the isocyanate-reactive component, e.g., the polyol,polyamine, or epoxy-containing component. The catalyst may be containedseparately from all other components or may be added to one or moreother components to form a mixture. In one embodiment, the catalyst isadded to the isocyanate-containing component. In another embodiment, thecatalyst is added to the isocyanate-reactive component. Suitablecatalysts include, but are not limited to, tin catalysts, for example,such as dibutyltin dilaurate; amine catalysts, for example, atrialkylamine such as triethylenediamine, triethylamine, tributylamine,or a mixture thereof; organic acids, for example, such as acetic acid,oleic acid, or a mixture thereof; delayed catalysts, for example, suchas POLYCAT™ SA-1, POLYCAT™ SA-102, and the like, or a mixture thereof;or combinations thereof. When a catalyst is present, it is added in anamount sufficient to catalyze or facilitate the reaction of thecomponents in the reactive mixture, preferably in an amount from about0.001% to 3%, based on the total weight of the first and secondreactable components.

[0080] Fillers added to one or more layers of the golf equipment, e.g.,a golf ball, typically include processing aids or compounds to affectrheological and mixing properties, the specific gravity (i.e.,density-modifying fillers), the modulus, the tear strength,reinforcement, and the like. A density adjusting filler may be used tocontrol the moment of inertia, and thus the initial spin rate of theball and spin decay. Fillers are typically polymeric or inorganic innature, and, when used, are typically present in an amount from about0.1 to 50 weight percent of the layer or portion in which they areincluded. Any suitable filler available to one of ordinary skill in theart may be used. Exemplary fillers include, but are not limited to,precipitated hydrated silica; clay; talc; glass fibers; aramid fibers;mica; calcium metasilicate; barium sulfate; zinc sulfide; lithopone;silicates; silicon carbide; diatomaceous earth; carbonates such ascalcium carbonate and magnesium carbonate; metals such as titanium,tungsten, aluminum, bismuth, nickel, molybdenum, iron, copper, boron,cobalt, beryllium, zinc, and tin; metal alloys such as steel, brass,bronze, boron carbide whiskers, and tungsten carbide whiskers; metaloxides such as zinc oxide, iron oxide, aluminum oxide, titanium oxide,magnesium oxide, and zirconium oxide; particulate carbonaceous materialssuch as graphite, carbon black, cotton flock, natural bitumen, andcellulose flock; micro balloons such as glass and ceramic; fly ash;cured, ground rubber; or combinations thereof.

[0081] Other additive ingredients such as accelerators, e.g., tetramethylthiuram, processing aids, processing oils, plasticizers,colorants, e.g., dyes and pigments, as well as other additives wellknown to the ordinary-skilled artisan may also be used in the presentinvention in amounts sufficient to achieve the purpose for which theyare typically used.

[0082] In an alternate embodiment, each component may include at leasttwo sets of precursor components that can be reacted to form at leasttwo different polymers of an interpenetrating polymer network, at leastone polymer being crosslinked. In addition, if any of the at least twocomponent sets include a mixture of precursor components, then thatmixture must be sufficiently non-reactive such that the sets ofprecursor components, when placed in contact with each other, can stillform an interpenetrating polymer network (IPN). Some interpenetratingpolymer networks form so quickly as to necessitate formation by areaction injection molding (RIM) method according to the invention.Additional descriptions of IPN compositions useful for golf equipment,or components thereof, according to the invention include thosedescribed in concurrently-filed U.S. patent application No. 09/______,entitled “Golf Balls Containing Interpenetrating Polymer Networks,” toM. Kuntimaddi et al., the disclosure of which is incorporated herein byexpress reference thereto.

[0083] In one embodiment, the golf equipment of the present inventionmay optionally include a foamed material. This foamed material mayadvantageously be made using the materials of the invention, as detailedherein. Suitable components of the foamed material may include thosedescribed in co-pending U.S. patent application Ser. No. 09/565,108,filed on May 4, 2000, the entire disclosure of which is incorporatedherein by reference hereto, although the foamed material will beprocessed by a method according to the present invention. For example,an IPN can be foamed and used to form golf equipment, or a portionthereof In addition, when the golf equipment of the invention includes afoamed material, the curing agent components may also include water.

[0084] When the golf equipment includes a foamed layer or portion, thefoamed layer or portion may be an open-cell, a closed-cell, or amicrocellular foam; the components may also include various foamingagents or blowing agents which may be readily selected by one ofordinary skill in the art, or which may include, but are not limited to,non-reactive gases, for example, such as freon, nitrogen, helium, carbondioxide, or the like, or combinations thereof. Foamed materials may alsoinclude microspheres added in with one or more of the components.Polymeric, ceramic, metal, and glass microspheres may be solid orhollow, and filled or unfilled. Particularly suitable microcellularmaterials include those described in co-pending U.S. patent applicationSer. No. 09/565,108, filed on May 4, 2000, previously incorporatedherein by reference. In a preferred embodiment, the foamed layer orportion has a specific gravity of not more than about 1, more preferablynot more than about 0.8, most preferably not more than 0.5.

[0085] In one embodiment, the golf equipment made according to theinvention, or a portion thereof, has a thickness less than about 0.065inches, alternately less than 0.01 inches. In particular, a layer of agolf ball, such as the cover, or a coating on a golf club face, can beprepared with the reaction injection molded material of the invention.

[0086] When the golf equipment is a golf ball, the center of the golfball may be fluid-filled. The fluid-filled golf ball may advantageouslycontain a fluid, for example, as disclosed in co-pending U.S.application Ser. No.09/496,353, filed Feb. 2, 2000, the entiredisclosure of which is incorporated herein by reference hereto, whichfluid may also possess some or all the properties detailed therein,e.g., such as fluid water activity, center fluid content, density, orspecific gravity, or the like, or a combination thereof. The core of thegolf ball may also be wound or non-wound.

[0087] Additionally, when butadiene rubber is used in one or more layersof the golf equipment, typically of golf balls, prepared according tothe present invention, the uncured rubber typically has a Mooneyviscosity greater than about 20, preferably greater than about 30, andmore preferably greater than about 40. In one embodiment, the Mooneyviscosity is about 40 to 60. Mooney viscosity is typically measuredaccording to ASTM D1646-99. Such materials can preferably be included inone or more core layers.

[0088] In another embodiment, the moisture vapor transmission rate(MVTR) or fluid permeation rate of a layer or coating of the gelled orsolidified reactive mixture is typically less than about 1,000(g.mil)/(100 in².day), preferably less than about 750 (g.mil)/(100in².day), more preferably less than about 500 (g.mil)/(100 in².day). Forcomparison purposes, it is desirable to test samples having a thicknessof approximately 0.02 inches (20 mils) to relatively assess permeationor MVTR values.

[0089] Also when the golf equipment contains multiple layers, forexample, such as in a multi-layer golf ball, a surface treatment betweenany two layers may be effected to improve the adhesion between thoselayers. The surface treatment may include mechanical abrasion, e.g.,such as sandblasting; plasma treatment, including treatment atatmospheric pressure; corona treatment; flame treatment; wet chemicalsurface modification; application of adhesives or adhesion promoters,e.g., such as those available commercially as EASTMAN 343-1, EASTMAN343-3, EASTMAN 515-2 (all from Eastman Chemical Co. of Kingsport,Tenn.), BAYER 8173, BAYER U42, BAYER U53, BAYER 140AQ (all from BayerCorp. of Pittsburgh, Pa.), RICOBOND (from Ricon Resins, Inc. of GrandJunction, Col.), WITCOBOND (from Witco Corp. of Greenwich Conn.), or thelike, or a combination thereof. Advantageously, the surface treatmentmay be effected as recited in co-pending U.S. application Ser. No.09/389,058, filed on Sep. 2, 1999, the entire disclosure of which isincorporated herein by reference hereto.

[0090] When the golf equipment includes golf balls, the resultant golfballs prepared according to the invention typically will typically havedimple coverage greater than about 60 percent, preferably greater thanabout 65 percent, and more preferably greater than about 70 percent.Optionally, the golf balls also have a cover material hardness fromabout 15 Shore A to 85 Shore D, or a flexural modulus (measuredaccording to ASTM D6272-98) of greater than about 500 psi (3.4 MPa). Insome cases, the flexural modulus of the reaction injection molded golfequipment, or portion thereof, can be less than about 5,000 psi (34MPa). In other cases, the flexural modulus of the reaction injectionmolded golf equipment, or portion thereof, can be less than about300,000 psi (2.1 GPa). The golf balls also typically have a coefficientof restitution of greater than about 0.7, preferably greater than about0.75, and more preferably greater than about 0.78, at an initialvelocity of 125 ft/s. The golf balls also typically have an Atticompression of at least about 40, preferably from about 50 to 120, morepreferably from about 60 to 100.

[0091] When the golf equipment is a golf ball, the golf ballconstruction may be such that it has “high spin” or “low spin”characteristics. In an embodiment when the golf balls according to theinvention include more than one cover layer, the golf ball willtypically include an outer cover layer having a first material hardnessand another layer beneath the outer cover layer, be it an inner coverlayer or an intermediate layer, having a second material hardness. Inone embodiment, the first material hardness is greater than the secondmaterial hardness, wherein the golf ball is then typically characterizedas a “low spin” ball, and the ball has lower spin when struck by adriver than the “high spin” embodiment. In an alternate embodiment, thefirst material hardness may be at least about 55 Shore D, or the secondmaterial hardness may be up to about 55 Shore D. In another embodiment,the second material hardness is greater than the first materialhardness, wherein the golf ball is then typically characterized as a“high spin” ball, and the ball has higher spin when struck by a driverthan the “low spin” embodiment. In an alternate embodiment, the secondmaterial hardness may be at least about 55 Shore D, or the firstmaterial hardness may be up to about 55 Shore D.

[0092] In yet another embodiment, both the first and the second materialhardness are above about 55 Shore D. In still another embodiment, boththe first and the second material hardness are below about 60 Shore D.All such hardnesses are measured on the material preferably using ASTMD2240-00.

[0093] Depending on the desired properties, golf equipment, primarilygolf balls, prepared according to the invention can exhibitsubstantially the same or higher resilience, or coefficient ofrestitution (“COR”), with a decrease in compression or modulus, comparedto equipment of conventional construction. Additionally, golf equipmentprepared according to the invention can also exhibit substantiallyhigher resilience, or COR, without an increase in compression, comparedto equipment of conventional construction. Another measure of thisresilience is the loss tangent, or tan δ, which is obtained whenmeasuring the dynamic stiffness of an object. Loss tangent andterminology relating to such dynamic properties is typically describedaccording to ASTM D4092-90. Thus, for golf balls, a lower loss tangentindicates a higher resiliency, thereby indicating a higher reboundcapacity. Low loss tangent indicates that most of the energy imparted toa golf ball from the club is converted to dynamic energy, i.e., launchvelocity and resulting longer distance. The rigidity or compressivestiffness of a golf ball may be measured, for example, by the dynamicstiffness. A higher dynamic stiffness indicates a higher compressivestiffness. To produce golf balls having a desirable compressivestiffness, the dynamic stiffness of the crosslinked polybutadienereaction product can be less than about 50,000 N/m at about −50° C. Inone preferred embodiment, the dynamic stiffness can be from about 10,000N/m to 40,000 N/m at about −50° C., more preferably from about 20,000N/m to 30,000 N/m at about −50° C.

[0094] The dynamic stiffness is similar in some ways to dynamic modulus.Dynamic stiffness is dependent on probe geometry as described herein,whereas dynamic modulus is a unique material property, independent ofgeometry. The dynamic stiffness measurement has the unique attribute ofenabling quantitative measurement of dynamic modulus and exactmeasurement of loss tangent at discrete points within a sample article.In the case of this invention, the article is at least a portion of agolf ball core. The polybutadiene reaction product preferably has a losstangent below about 0.1 at about −50° C., and more preferably belowabout 0.07 at about −50° C.

[0095] As is well known to those of ordinary skill in the art, thetime-temperature superposition principle may be used to emulatealternative deformation rates. Particularly for golf ball portionsincluding polybutadiene, a 1-Hz oscillation at temperatures betweenabout 0° C. and −50° C. are believed to be qualitatively equivalent togolf ball impact rates. Therefore, measurement of loss tangent anddynamic stiffness at about 0° C. to −50° C. may be used to accuratelyanticipate golf ball performance, preferably at temperatures from about−20° C. to −50° C.

[0096] The golf equipment, or the reaction injection molded portionthereof, e.g., a golf ball or golf ball layer, typically has a dynamicshear storage modulus of at least about 10⁴ dynes/cm², preferably fromabout 10⁴-10¹⁰ dyn/cm², and more preferably from about 10⁶ to 10⁸dyn/cm², when measured at about 23° C. and a frequency of 1 Hz. Thereaction injection molded golf ball or golf ball layer also typicallyhas a loss tangent no greater than about 1 at any temperature,preferably from about 0.01 to 0.5 at about 23° C., and more preferablyfrom about 0.01 to 0.1 at about 23° C.

[0097] Another aspect of the invention relates to a grid scaffoldingpresent in any portion of golf equipment that is below the outersurface. In the case of a golf ball, for example, the grid scaffoldingmay be present in any layer other than the outer cover layer (when morethan one cover layer is present). The incorporation of this gridscaffolding in golf equipment according to the invention canadvantageously improve performance properties or reduce the cost ofmanufacturing the golf equipment. For example, when the golf equipmentis a golf ball, the presence of a grid scaffolding in one of the golfball layers modifies at least one of the golf ball spin, feel, distance,or velocity. The modification of these golf ball properties may changewith such characteristics as the density, the mechanical properties(e.g., compressive modulus, flexural modulus, strength, viscoelasticresponse, and the like), the thickness, the continuity, or thecompatibility of the grid with the materials surrounding it. As aresult, other properties or characteristics of the golf ball may beinfluenced, e.g., such as the moment of inertia, spin rate, ball weight,or the like, or combinations thereof. The grid scaffolding may becontinuous or non-continuous, preferably non-continuous, and istypically symmetrical about a central mirror plane.

[0098] The grid scaffolding may also advantageously allow the materialdisposed above and beneath it to have an intermediate interface withwhich to interact. In addition, the discontinuities, e.g., gaps, ifpresent, in the grid scaffolding may be filled with another material toallow the material disposed above and beneath it to have twointermediate interfaces with which to interact. Without being bound bytheory, it is believed that the mechanical or structural integrity ofthe connection between the material disposed above and beneath the gridscaffolding may be desirably tailored to alter, for example, theproperties of the golf equipment as a whole. In addition, the physical(or optionally chemical, if there is complementary functionalitypresent) adhesion present between the grid scaffolding, the materialdisposed above and beneath, and optionally another material filledwithin the grid, may be effected without further adhesive, chemical,abrasive, or other treatment of the surfaces involved. It is believedthat sufficient adhesion may occur because the surface area for contactbetween all the materials in such a composite can be increased by usingsuch a grid scaffolding, as compared to adhesion between traditionallayers. Additional treatments to increase adhesion of any of thesecomponents can, of course, be used if desired. In another embodiment,where the grid is continuous, adhesion and mechanical integrity canstill be effected, although without another intermediate material.

[0099] The grid scaffolding according to the invention may be made byany appropriate manufacturing technique known to those of ordinary skillin the art. The cross-sectional shape or texture of the grid scaffoldingmay vary and can include a corrugated shell, preferably a bi-corrugatedshell, a ribbed shell, a square-edged shell, or the like, or acombination thereof. The three-dimensional shape of the grid scaffoldingcan advantageously be tailored to the particular golf equipment in whichit is incorporated. For example, the grid may be spherical orhemispherical for use in a golf ball, flat for use in a golf club heador a golf shoe sole, or cylindrical or frusto-conical for use in a golfclub shaft, or the like.

[0100] Referring to FIG. 1, a golf ball 10 of the present invention caninclude a center 12 and a cover 16 surrounding the center 12. Referringto FIG. 2, a golf ball 20 of the present invention can include a center22, a cover 26, and at least one intermediate, or intermediate, layer 24disposed between the cover and the center. Each of the cover and centerlayers in FIGS. 1 or 2 may include more than one layer (not shown);i.e., the golf ball can be a conventional three-piece wound ball, atwo-piece ball, a ball having a multi-layer core and an intermediatelayer or layers, etc. Also, FIG. 3 shows a golf ball 30 of the presentinvention including a center 32, a cover 38, and two intermediate layers34, 36 disposed therebetween. In another embodiment, the ball 30illustrates a two part center 32,34, an intermediate layer 36, and acover 38. The two part center can include, for examples, two solidlayers, a solid layer 32 and a wound layer 34 or grid 34 disposed aboutit, or a fluid-filled center 32 and a shell 34 to contain the fluid.Additionally, although FIGS. 1-3 show golf balls with only one coverlayer, it will be appreciated that any number or type of cover layersmay be used. In each of these FIGS. and embodiments, at least one layerincludes a reaction injection molded material or is formed by reactioninjection molding.

[0101] Any one of the center, core, intermediate layers, or inner coverlayers (not the outer cover layer, when more than one cover layer ispresent), may contain dual hemispheres of a grid scaffolding (i.e., thusforming a non-continuous spherical grid), one hemisphere of which isshown, for example, in FIG. 4. Alternately, one continuous sphericalgrid scaffolding may be used instead of a non-continuous grid formedfrom two opposing hemispherical scaffolds. In one embodiment, anintermediate or an inner cover layer (when more than one cover layer ispresent) of a multi-layer golf ball according to the invention containsdual hemispheres of this grid scaffolding. In this embodiment, the layerthat contains this grid scaffolding (i.e., the grid layer), may alsocontain a polymeric material disposed about or beneath the dualhemispherical grid scaffolding. In a preferred embodiment, the polymericmaterial penetrates corrugations in the dual hemispheres of the gridscaffolding and is disposed about, through, and beneath the gridscaffolding in the grid layer.

EXAMPLES

[0102] The following examples are only representative of the methods andmaterials for use in golf ball compositions and golf balls of thisinvention, and are not to be construed as limiting the scope of theinvention in any way.

Example 1

[0103] Polyurethane RIM Composition for Use in One or More Golf BallLayers COMPONENTS EQUIVALENTS Quasi-Prepolymer 1    Polyol 0.215 Diamine0.735 Organometallic Catalyst 0.05% based on total of first threecomponents Tertiary Amine Catalyst 0.05% based on total of first threecomponents Filler  3.5% based on total of first three components

[0104] The quasi-prepolymer of Example 1 is, in one embodiment, anaromatic diisocyanate-endcapped, 2,000-molecular-weight (number average)polyether glycol, more specifically an MDI/PTMEG quasi-prepolymer, e.g.,such as one which has an isocyanate content of about 15.3% and iscommercially available from Polyurethane Specialties Co., Inc., ofLyndhurst, N.J. The polyol of Example 1 is, in one embodiment, apolyether polyol, especially a polytetramethylene glycol, and has anumber average molecular weight above about 400 g/mol, in one embodimentapproximately 2,000 g/mol. The diamine can be any suitable diamine, inone embodiment being aromatic and liquid, e.g., such as ETHACURE™ 100,which commercially available from Albemarle Corp., of Baton Rouge, La.The organometallic catalyst is preferably dibutyltin dilaurate, e.g.,such as DABCO® T-12, and the amine catalyst preferably includes atertiary amine, e.g., such as DABCO® 33-LV, which is a 33% solution oftriethylenediamine in dipropylene glycol, both of which catalystexamples are commercially available from Air Products & Chemicals, Inc.,of Allentown, Pa. The filler is, in one embodiment, a white dispersioncontaining finely dispersed pigment in the form of a paste, e.g., suchas in HCC-19584, which is commercially available from PolyOne ofMassillion, Ohio.

[0105] The quasi-prepolymer is added to a first container separate fromthe polyol and diamine components, which are added to a secondcontainer. The two catalysts and the filler components may each be addedto either container, although generally these three components will allbe added to the second container along with the polyol and diaminecomponents. The contents of the first container and second container aremixed and immediately injected into a mold cavity to form a layer of agolf ball, preferably a cover layer, more preferably the outer coverlayer. Within about 60 seconds, at any temperature at or above ambienttemperature, the layer is substantially polymerized and/or crosslinkedto allow demolding of the golf ball, or portion thereof, containing areaction-injection-molded layer.

[0106] It is to be understood that the invention is not to be limited tothe exact configuration as illustrated and described herein. Forexample, it should be apparent that a variety of materials would besuitable for use in the composition or method of making the golfequipment according to the Detailed Description of the PreferredEmbodiments. Accordingly, all expedient modifications readily attainableby one of ordinary skill in the art from the disclosure set forthherein, or by routine experimentation therefrom, are deemed to be withinthe spirit and scope of the invention as defined by the appended claims.

What is claimed is:
 1. A method for forming golf equipment, or a portionthereof, which comprises: providing a first reactable componentcomprising an isocyanate-containing compound; and a second reactablecomponent comprising at least one of a polyol, polyamine, orepoxy-containing compound; and combining the reactable componentstogether to form a reactive mixture; and injecting the reactive mixtureinto a cavity or mold having a desired shape within about 60 secondsafter the combining to avoid substantial gelation or solidification soas to provide at least a portion of the golf equipment, wherein theisocyanate-containing compound comprises ethylene diisocyanate,propylene-1,2-diisocyanate, tetramethylene-1,4-diisocyanate,1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylenediisocyanate, dodecane-1,12-diisocyanate, 2,2,4-trimethylhexamethylenediisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4,4-trimethylenediisocyanate, cyclobutane-1,3-diisocyanate,cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, methylcyclohexylene diisocyanate,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane, isophoronediisocyanate, 4,4′-diphenylmethane diisocyanate, polymeric4,4′-diphenylmethane diisocyanate, carbodiimide-modified liquid4,4′-diphenylmethane diisocyanate, p-phenylene diisocyanate, m-phenylenediisocyanate, toluene diisocyanate, 3,3′-dimethyl-4,4′-biphenylenediisocyanate, naphthalene diisocyanate, xylylene diisocyanate, tetracenediisocyanate, napthalene diisocyanate, anthracene diisocyanate, theisocyanurate of toluene diisocyanate, the isocyanurate of ahexamethylene diisocyanate, the uretdione of toluene diisocyanate, theuretdione of 1,6-hexamethylene diisocyanate, or a mixture thereof. 2.The method of claim 1, wherein the isocyanate-containing componentcomprises a polyisocyanate or a prepolymer or quasi-prepolymercontaining the reaction product of a polyol, polyamine, orepoxy-containing compound with at least one polyisocyanate.
 3. Themethod of claim 1, wherein the isocyanate-containing component containsgreater than about 14% isocyanate by weight, compared to the totalweight of the isocyanate-containing component.
 4. The method of claim 1,wherein the isocyanate-containing compound comprises an aliphaticpolyisocyanate, 4,4′-diphenylmethane diisocyanate, m-phenylenediisocyanate, p-phenylene diisocyanate, toluene diisocyanate, or amixture thereof.
 5. The method of claim 1, wherein the golf equipmentcomprises a golf ball, or a portion thereof.
 6. The method of claim 5,wherein the golf ball has at least one of a compression from about 50 to120 or a coefficient of restitution of greater than about 0.7.
 7. Themethod of claim 5, wherein the golf ball comprises a solid orfluid-filled center, optionally at least one intermediate layer disposedabout the center, and at least one cover layer disposed about the centerand the optional intermediate layer, if present.
 8. The method of claim7, wherein the cover layer has a first material hardness and the layerdisposed immediately inside the cover layer has a second materialhardness, and wherein the first material hardness is no less than thesecond material hardness.
 9. The method of claim 7, wherein the coverlayer of the golf ball has a first material hardness and the layerdisposed immediately inside the cover layer has a second materialhardness, and wherein the first material hardness is at least 55 Shore Dor the second material hardness is up to 55 Shore D.
 10. The method ofclaim 7, wherein the cover layer has a first material hardness and thelayer disposed immediately inside the cover layer has a second materialhardness, and wherein the second material hardness is no less than thefirst material hardness.
 11. The method of claim 7, wherein the coverlayer of the golf ball has a first material hardness and the layerdisposed immediately inside the cover layer has a second materialhardness, and wherein the second material hardness is at least 55 ShoreD or the first material hardness is up to 55 Shore D.
 12. The method ofclaim 5, wherein the core of the golf ball has an outer diameter fromabout 1.55 inches to 1.67 inches.
 13. The method of claim 5, wherein theinjecting results in the formation of golf equipment, or a portionthereof, which has a thickness less than about 0.065 inches.
 14. Themethod of claim 5, wherein the second reactable component comprises afirst isocyanate-reactive compound having a molecular weight less thanabout 400 g/mol, and a second isocyanate-reactive compound having anumber average molecular weight of not less than about 400 g/mol. 15.The method of claim 14, wherein the second isocyanate-reactive compoundcomprises a polyether polyol, a hydroxy-terminated polybutadiene, apolyester polyol, a polycarbonate polyol, or a copolymer or a mixturethereof.
 16. The method of claim 15, wherein the polyether polyolcomprises poly(tetramethylene oxide) glycol, poly(ethylene oxide)glycol, poly(propylene oxide) glycol, poly(oxyethylene-oxypropylene)glycol copolymers, or mixtures or copolymers thereof; or wherein thepolyester polyol comprises polyethylene adipate glycol, polypropyleneadipate glycol, polybutylene adipate glycol, poly(ethyleneadipate-propylene adipate) glycol, poly(hexamethylene adipate) glycol, apolycaprolactone polyol, or mixtures or copolymers thereof; or whereinthe polycarbonate polyol comprises poly(phthalate carbonate) glycol,poly(hexamethylene carbonate) glycol, polycarbonate glycols containingbisphenol A, or mixtures or copolymers thereof.
 17. The method of claim5, wherein the gelation or solidification time of the reactive mixtureis from about 0.25 seconds to 30 seconds.
 18. The method of claim 5,wherein the gelation or solidification time of the reactive mixture isfrom about 1 second to 5 seconds.
 19. The method of claim 5, wherein theviscosity of each of the reactable components, or mixture thereof, isnot more than about 20,000 cPs at ambient temperature or at atemperature at which the reactable components are combined.
 20. Themethod of claim 5, wherein the viscosity of each of the reactablecomponents, or mixture thereof, is from about 25 cPs to 10,000 cPs at atemperature at which the reactable components are combined.
 21. Themethod of claim 5, wherein the viscosity index of two of the reactablecomponents is from about 1000 to 1 at ambient temperature or at atemperature at which the reactable components are combined.
 22. Themethod of claim 5, wherein the golf ball, or a portion thereof, has anMVTR of less than about 500 (g.mil)/(100 in².day).
 23. The method ofclaim 5, which further comprises adding from about 0.1% to 50% by weightof a filler material.
 24. The method of claim 5, which further comprisesadding at least one catalyst to facilitate the reaction between the atleast two reactable components when they are combined.
 25. The method ofclaim 24, wherein the catalyst is present in an amount from about 0.001%to 3% by weight and comprises a metal catalyst, an amine catalyst, anorganic acid, a delayed catalyst, or a combination thereof.
 26. Themethod of claim 5, wherein the isocyanate-containing component comprisesa polyisocyanate or a prepolymer or quasi-prepolymer containing thereaction product of a polyol, polyamine, or epoxy-containing compoundwith at least one polyisocyanate.
 27. The method of claim 5, wherein theisocyanate-containing component contains greater than about 14%isocyanate by weight, compared to the total weight of theisocyanate-containing component.
 28. The method of claim 5, wherein theisocyanate-containing compound comprises an aliphatic polyisocyanate,4,4′-diphenylmethane diisocyanate, m-phenylene diisocyanate, p-phenylenediisocyanate, toluene diisocyanate, or a mixture thereof.
 29. A methodfor forming golf equipment, or a portion thereof, which comprises:providing a first reactable component comprising a low free isocyanatemonomer composition; and a second reactable component comprising atleast one polyol, polyamine, or epoxy-containing compound; combining thereactable components together to form a reactive mixture; and injectingthe reactive mixture into a cavity or mold having a desired shape withinabout 60 seconds after the combining to avoid substantial gelation orsolidification so as to provide at least a portion of the golfequipment.
 30. A method for forming golf equipment, or a portionthereof, which comprises: providing a first reactable componentcomprising an isocyanate-containing compound; and a second reactablecomponent comprising at least one polyol, polyamine, or epoxy-containingcompound; combining the reactable components together to form a reactivemixture; and injecting the reactive mixture into a cavity or mold havinga desired shape within about 60 seconds after the combining to form apolymer or copolymer containing a hard segment and a soft segment and toavoid substantial gelation or solidification so as to provide at least aportion of the golf equipment, wherein the hard segment is present in anamount from about 5% to 60%, based on the total weight of the polymer,or wherein the soft segment is present in an amount from about 40% to95%, based on the total weight of the polymer.
 31. A method for forminggolf equipment, or a portion thereof, which comprises: providing a firstreactable component comprising an isocyanate-containing compound, and asecond reactable component comprising at least one polyol, polyamine, orepoxy-containing compound, wherein each reactable component has aviscosity not more than about 5,000 cPs at a temperature of about 150°F.; combining the reactable components together to form a reactivemixture; and injecting the reactive mixture into a cavity or mold havinga desired shape within about 60 seconds after the combining to avoidsubstantial gelation or solidification so as to provide at least aportion of the golf equipment.
 32. A method for forming golf equipment,or a portion thereof, which comprises: providing a first reactablecomponent comprising an isocyanate-containing compound, and a secondreactable component comprising at least one polyol, polyamine, orepoxy-containing compound; combining the reactable components togetherto form a reactive mixture; and injecting the reactive mixture at aninjection pressure of not more than about 2,500 psi into a cavity ormold having a desired shape within about 60 seconds after the combiningto avoid substantial gelation or solidification so as to provide atleast a portion of the golf equipment.
 33. A method for forming golfequipment, or a portion thereof, which comprises: providing at least twosets of precursor components that can be reacted to form at least twodifferent polymers of an interpenetrating polymer network, at least onepolymer being crosslinked; combining the sets of precursor componentstogether to form a reactive mixture; and injecting the reactive mixtureinto a cavity or mold having a desired shape within about 60 secondsafter the combining to avoid substantial polymerization, gelation, orsolidification, so as to provide at least a portion of the golfequipment.
 34. The method of claim 33, wherein the at least two sets ofprecursor components comprise a first reactable component whichcomprises an isocyanate-containing compound, and a second reactablecomponent, which comprises an isocyanate-reactive compound.
 35. A methodfor forming golf equipment, or a portion thereof, which comprises:providing at least two reactable components that, when combined, canform a foamed polymeric material; combining the reactable componentstogether to form a reactive mixture; and injecting the reactive mixtureinto a cavity or mold having a desired shape within about 60 secondsafter the combining to avoid substantial gelation or solidification andsuch that the reactive mixture forms a foamed polymeric material, so asto provide at least a portion of the golf equipment.
 36. The method ofclaim 35, wherein the foamed polymeric material comprises an open-cell,closed-cell, or microcellular foam, or a combination thereof.
 37. Themethod of claim 35, wherein the foamed polymeric material has a specificgravity of not more than about
 1. 38. Golf equipment prepared by theprocess of claim
 1. 39. A multi-layer golf ball prepared by the processof claim
 5. 40. A multi-layer golf ball comprising at least one corelayer and at least one cover layer disposed about the at least one corelayer, wherein at least one of the golf ball layers about one of thecore layers comprises a reaction injection molded material.
 41. The golfball of claim 40, wherein the at least one cover layer comprises anouter cover layer disposed about an inner cover layer.
 42. The golf ballof claim 40, wherein the golf ball comprises a solid or fluid-filledcore.
 43. The golf ball of claim 40, which further comprises at leastone intermediate layer disposed between the at least one core layer andthe at least one cover layer.
 44. The golf ball of claim 43, wherein theintermediate layer is a wound layer or comprises areaction-injection-molded material.
 45. A method for forming golfequipment, or a portion thereof, which comprises: providing a firstreactable component comprising an isocyanate-containing compound; and asecond reactable component comprising at least one of a polyol,polyamine, or epoxy-containing compound; and combining the reactablecomponents together to form a reactive mixture; and injecting thereactive mixture into a cavity or mold having a desired shape withinabout 60 seconds after the combining to avoid substantial gelation orsolidification so as to provide at least a portion of the golfequipment, wherein the isocyanate-containing compound comprises: adiisocyanate having the generic structure, O═C═N—R—N═C═O, where R is acyclic, aromatic, or linear branched or unbranched hydrocarbon chaineach having a moiety containing from about 1 to 20 carbon atoms; adimeric or multimeric adduct of a diisocyanate; a triisocyanate orhigher functional polyisocyanate that is not an adduct of adiisocyanate; or a mixture thereof.
 46. Golf equipment, or a portionthereof, which comprises: a first reactable component comprising anisocyanate-containing compound; and a second reactable componentcomprising at least one of a polyol, polyamine, or epoxy-containingcompound, wherein the golf equipment, or portion thereof, is formed byreaction injection molding of the first and second reactable components,which react with each other after contact sufficiently to besubstantially gelled or solidified within about 60 seconds, and whereinthe isocyanate-containing compound comprises: a diisocyanate having thegeneric structure, O═C═N—R—N═C═O, where R is a cyclic, aromatic, orlinear branched or unbranched hydrocarbon chain each having a moietycontaining from about 1 to 20 carbon atoms; a dimeric or multimericadduct of a diisocyanate; a triisocyanate or higher functionalpolyisocyanate that is not an adduct of a diisocyanate; or a mixturethereof.
 47. The golf equipment of claim 46, comprising a portion of amulti-layer golf ball.